Electronic Register Device for Recording Jaw Movements

ABSTRACT

An electronic register device for recording movements of the lower jaw of a person relative to the upper jaw of the person, the device having a bite fork for recording a position of the upper jaw relative to reference points on the head of the person, wherein the bite fork is designed to receive a plastic compound for recording an impression of the dentition of the upper jaw

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an electronic register device for recordingmovements of the lower jaw of a person relative to the upper jaw of theperson, which register device has a bite fork for recording a positionof the upper jaw relative to reference points on the head of the person,wherein the bite fork is designed to receive a plastic compound forrecording an impression of the dentition of the upper jaw, and alower-jaw attachment for recording movements of the lower jaw relativeto the upper jaw.

2. Related Technology

To produce tooth replacements such as crowns and bridges, it is known toform models of the dentition of an upper jaw and of the associated lowerjaw from wax and to optimize the shape of these models in anarticulator, through articulation movements, until a harmonious movementof the tooth shapes in relation to one another is obtained. This isreferred to as a functional comparison. In this way, it is subsequentlypossible to avoid time-consuming grinding work in the mouth of thepatient concerned.

According to the prior art, the tooth shape optimized in the articulatoris then recorded by scanning and, in a further step, the desired toothreplacement, for example the crown or bridge, is produced, preferablyfrom ceramic, using a CAD CAM milling/grinding machine and the datarecorded by the scanning procedure.

A kind of “virtual articulator” is also known. This involves softwarewith which a movement of the two scanned plaster models of the upper jawand lower jaw relative to each other can be simulated. To be able todetermine adjustment data for this virtual articulator, it is firstnecessary to produce the corresponding plaster models of the dentitionof the upper jaw and lower jaw; the adjustment values then have to bedetermined using these plaster models and a mechanical articulator. Thisrequires quite a lot of work.

WO 2007/020091 A1 discloses an electronic register device which is soldby the applicant under the trade name “ARCUS digma” and which is used toadjust articulators. An electronic analysis of the position of the lowerjaw can be performed with this device. In order to measure the movementsof the lower jaw relative to the upper jaw, a carrier frame is connectedin each case to the upper jaw and the lower jaw. The carrier frameconnected on the upper part of the head to the upper jaw, andhereinafter also called the “head part,” is provided with fourmicrophones in the form of ultrasound receivers, while the carrier frameconnected to the lower jaw, and hereinafter also called the “lower-jawattachment”, is provided with three corresponding ultrasoundtransmitters. The twelve paths between the three transmitters and thefour microphones are evaluated in respect of their changes in lengthduring movements of the lower jaw relative to the upper jaw. FIGS. 2A,2B, 2C, and 2D show sketches of the lower-jaw attachment from differentperspectives.

The head part includes a base element with support elements forsupporting the head part on the head of the person concerned or of apatient. These support elements can in particular comprise two rearwardbearing elements, which are designed to rest in the area of the twoears, and a nose support, which is designed to rest on the upper nose.

Moreover, the known electronic register device ARCUS digma includes abite fork, which serves to record the position of the dentition of theupper jaw relative to the auditory canals. FIGS. 1A, 1B, 1C, and 1D showsketches of the bite fork from different perspectives.

SUMMARY OF THE INVENTION

The invention provides a system by which tooth replacements, for examplecrowns and bridges, can be produced more easily. The invention alsopermits improved production of drill jigs in implantology.

Accordingly, the invention provides an electronic register device forrecording movements of the lower jaw of a person relative to the upperjaw of the person. The register device has a bite fork for recording aposition of the upper jaw relative to reference points on the head ofthe person, wherein the bite fork is designed to receive a plasticcompound for recording an impression of the dentition of the upper jaw.Moreover, the register device has a lower-jaw attachment for recordingmovements of the lower jaw relative to the upper jaw. In addition, theregister device has a reference body, wherein the register device isdesigned so that the reference body can be connected in a fixed positionto the bite fork, with the bite fork and the reference body connectedthereto in a fixed position being designed in such a way that both theimpression and also the reference body can be recorded by a scanningprocedure, in particular by a continuous scanning procedure.

By scanning the reference body and the impression, it is possible tomaintain or establish a relationship between the scanned impression andthe movement data recorded by the register device. In this way,adjustment values for a virtual articulator can be determined withouthaving to produce plaster models of the dentition of the upper and lowerjaws.

Moreover, the register device according to the invention allowsthree-dimensional data of an X-ray system to be superposed with themovement data of the register device. This facilitates the production ofdrill jigs in implantology.

The reference body preferably has first form-fit elements, and the bitefork has second form-fit elements, such that, in order to produce thepositionally fixed connection of the reference body to the bite fork,the first form-fit elements can be brought into a form-fit engagementwith the second form-fit elements. The positionally fixed connectionbetween the reference body and the bite fork can thus be produced in aparticularly simple and user-friendly manner.

The register device preferably is further designed so that the referencebody can also alternatively be connected in a fixed position to thelower-jaw attachment.

The lower-jaw attachment preferably also has third form-fit elements,such that, to produce the positionally fixed connection of the referencebody to the lower-jaw attachment, the first form-fit elements can bebrought into another form-fit engagement with the third form-fitelements. The positionally fixed connection between the reference bodyand the lower-jaw attachment can thus be produced in a particularlysimple and user-friendly manner.

The reference body advantageously has several, preferably at leastthree, pin-shaped or hemispherical scan elements, which are preferablydesigned to protrude from a plane surface of the reference body. Atleast two of the scan elements preferably have different shapes.

According to another aspect of the invention, an electronic registerdevice is provided for recording movements of the lower jaw of a personrelative to the upper jaw of the person, the register device having abite fork for recording a position of the upper jaw relative toreference points on the head of the person, wherein the bite fork isdesigned to receive a plastic compound for recording an impression ofthe dentition of the upper jaw. Moreover, the register device has alower-jaw attachment for recording movements of the lower jaw relativeto the upper jaw. The bite fork has a first reference body, which isconnected in a fixed position to the rest of the bite fork, and thelower-jaw attachment has a second reference body, which is connected ina fixed position to the rest of the lower-jaw attachment. The bite forkis designed in such a way that both the impression and also the firstreference body can be recorded by a scanning procedure, in particular acontinuous scanning procedure.

The first reference body and the second reference body preferably eachhave several, highly preferably in each case at least three, pin-shapedor hemispherical scan elements, which are each preferably designed toprotrude from a plane surface of the reference body in question.

Moreover, at least two of the scan elements of the first reference bodypreferably have different shapes, and/or at least two of the scanelements of the second reference body have different shapes.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in more detail below on the basis ofillustrative embodiments and with reference to the drawings, in which:

FIGS. 1A to 1D show sketches of a bite fork from different perspectives,

FIGS. 2A to 2D show sketches of a lower-jaw attachment from differentperspectives,

FIG. 3A shows a bite fork with a first illustrative embodiment of areference body according to the invention,

FIG. 3B shows a bite fork with a second illustrative embodiment of areference body according to the invention,

FIG. 3C shows a lower-jaw attachment with a reference body according tothe first illustrative embodiment,

FIG. 3D shows a lower-jaw attachment with a reference body according tothe second illustrative embodiment,

FIG. 4 shows a perspective view of the reference body according to thefirst illustrative embodiment,

FIG. 5 shows a perspective view of the reference body according to thesecond illustrative embodiment,

FIGS. 6A to 6C show further sketches of the reference body according tothe first illustrative embodiment,

FIGS. 7A to 7C show further sketches of the reference body according tothe second illustrative embodiment,

FIG. 8 shows a block diagram illustrating the use of a bite fork withthe reference body according to the first illustrative embodiment,

FIG. 9 shows a sketch illustrating reference points between an “ARCUSdigma” and an articulator, and

FIG. 10 shows a sketch illustrating reference points of an articulator.

DETAILED DESCRIPTION

According to the invention, an electronic register device is providedfor recording movements of the lower jaw of a person relative to theupper jaw of the person. The register device can have the features ofthe “ARCUS digma” device mentioned in the introduction. In particular,the register device can include a corresponding head part, whichincludes a base element with support elements for supporting the headpart on the head of a patient. These support elements can in particularinclude two rearward bearing elements, which are designed to rest in thearea of the two ears, for example to rest in the external auditorycanals, and also a nose support, which is designed to rest on the uppernose.

The register device furthermore includes a bite fork, which is designedand used to record a position of the upper jaw relative to referencepoints on the head of the person. As has already been mentioned in theintroduction, FIGS. 1A to 1D show sketches of a known design of a bitefork 2 from different perspectives. The bite fork 2 is designed toreceive a plastic compound, for example wax or silicone, for recordingan impression of the dentition of the upper jaw. For this purpose, thebite fork 2 has a receiving surface 21 for receiving the plasticcompound, wherein the receiving surface 21 has a surface normal in adirection R; moreover, the bite fork 2 has another surface 23, thesurface normal of which likewise points in the direction R, wherein thebite fork 2 is designed in such a way that the other surface 23 islocated outside the oral cavity of the person when the bite fork 2 ispositioned for taking the impression of the dentition of the upper jaw.

The register device further includes a lower-jaw attachment. As hasalready been mentioned in the introduction, FIGS. 2A to 2D show sketchesof a known lower-jaw attachment 4 from different perspectives. Thelower-jaw attachment 4 serves for recording movements of the lower jawrelative to the upper jaw. The lower-jaw attachment has an angled,elongate contact area 41, which is intended to be connected, for exampleby an adhesive connection, to the anterior surfaces of the front teethof the lower jaw. Moreover, the lower-jaw attachment has a surface 43,which is oriented at least approximately in a plane fixed by theelongate contact area 41 and which is located outside the oral cavity ofthe person when the lower-jaw attachment 4 is connected as intended tothe teeth of the lower jaw.

The register device, in contrast to the “ARCUS digma” device, also has areference body. FIG. 4 shows a reference body 6 according to a firstillustrative embodiment. The register device is designed in such a waythat the reference body 6 can be connected in a fixed position, andpreferably reversibly in a fixed position, to the bite fork 2, asindicated in FIG. 3A. In other words, the design is such that thereference body 6 can be connected to the bite fork 2 in a definedposition relative to the latter.

In particular, a form-fit engagement can be provided for this purposebetween the reference body 6 and the bite fork 2. This permitsparticularly simple handling. For this purpose, as is indicated by wayof example in FIG. 6A, the reference body 6 can have first form-fitelements 62 and, as is indicated by way of example in FIG. 1A, the bitefork 2 can have second form-fit elements 22 which, in order to producethe form-fit engagement, can be connected in a defined manner to thefirst form-fit elements 62. The first form-fit elements 22 can be formedby at least three engagement elements, and the second form-fit elements22 can be formed by correspondingly shaped and congruent openings. Thispermits particularly simple handling when producing the positionallyfixed connection of the reference body 6 to the bite fork 2. FIGS. 6Band 6C show sketches of the reference body 4 from other perspectives.

Moreover, FIG. 3A indicates a corresponding impression 10 of thedentition of the upper jaw.

Provision is preferably made that the reference body 6, in order toproduce the positionally fixed connection, can be arranged on the othersurface 23 of the bite fork 2. For this purpose, the second form-fitelements 22 or the openings can be formed on or in the other surface 23of the bite fork 2.

The register device is designed in such a way that both the impression10 of the dentition of the upper jaw, recorded with the bite fork 2, andalso the reference body 6 can be recorded by a scanning procedure, inparticular by a scanning procedure in which the position of thereference body 6 relative to the impression 10 can be recorded. This isindicated diagrammatically in FIG. 8. Such a scanning procedure allows arelationship to be established between, on the one hand, the scannedimpression 10 and, on the other hand, the movement data recorded by theregister device. In this way, adjustment values for a virtualarticulator can be determined, in particular without having to produceplaster models of the dentition of the upper jaw and lower jaw.Moreover, the register device according to the invention allowsthree-dimensional data of an X-ray system to be superposed with themovement data of the register device. This facilitates production ofdrill jigs in implantology. For the assignment of the two systems ARCUSdigma and CAD CAM or ARCUS digma and 3D scan, the entire structuralcomponent consisting of the bite fork 2 and of the reference body 6 isscanned. The tooth impressions and on the teeth are recorded in relationto the scanner or reference body 6 in one scan.

The register device is preferably also designed in such a way that thereference body 6 can also be connected in a fixed position to thelower-jaw attachment 4, as is indicated by way of example in FIG. 3C.For this purpose, the lower-jaw attachment 4 can advantageously havethird form-fit elements 42, particularly in the form of openings, whichare shown by way of example in FIG. 2A and which are preferably shapedanalogously to the second form-fit elements 22 or the openings of thebite fork 2. In this way, the reference body 6 can be mountedparticularly easily either on the bite fork 2 or on the lower-jawattachment 4. The third form-fit elements 42 are advantageously formedon or at the surface 43 of the lower-jaw attachment 4.

The reference body 6 advantageously has several, preferably at leastthree, pin-shaped or hemispherical scan elements 64, which arepreferably designed to protrude from a plane surface 66 of the referencebody 6. The configuration is preferably such that the scan elements 64are arranged or designed to protrude in direction R from the rest of thereference body 6 or the plane surface 66 when the reference body 6 isconnected in a fixed position to the bite fork 2. At least two of thescan elements 64 advantageously have different shapes. For instance, asis indicated by way of example in FIGS. 4, 6A, and 6C, pins of differentlengths can be provided as scan elements 64.

FIG. 5 shows a reference body 8 according to a second illustrativeembodiment. This reference body 8 can have scan elements 84, which aredesigned analogously to the scan elements 64 in the first illustrativeembodiment. Moreover, the reference body 8 according to the secondillustrative embodiment can have corresponding first form-fit elements82 or engagement elements, as are indicated in FIG. 7A. The referencebody 8 according to the second illustrative embodiment is shown in FIG.3B connected to the bite fork 2 and in FIG. 3D connected to thelower-jaw attachment 4. FIGS. 7B and 7C show other views of thereference body 8 according to the second illustrative embodiment.

FIG. 9 shows an assignment of reference points between the electronicregister device and an articulator. A corresponding system ofcoordinates is shown in sketch form in FIG. 10.

As an alternative to the above-described reference body 6 or 8,provision can be made that the bite fork of the electronic registerdevice has a first reference body, which is connected in a fixedposition to the rest of the bite fork, and that the lower-jaw attachmenthas a second reference body, which is connected in a fixed position tothe rest of the lower-jaw attachment, wherein the bite fork is designedin such a way that both the impression and also the first reference bodycan be recorded by a corresponding scanning procedure. The firstreference body can advantageously be formed integrally with the rest ofthe bite fork, and the second reference body can be formed integrallywith the lower-jaw attachment. The two reference bodies preferably eachhave scan elements, which are designed analogously to theabove-described scan elements 64 of the reference body 6 according tothe first illustrative embodiment.

1. Electronic register device for recording movements of the lower jawof a person relative to the upper jaw of the person, the register devicecomprising: a bite fork for recording a position of the upper jawrelative to reference points on the head of the person, wherein the bitefork is designed to receive a plastic compound for recording animpression of the dentition of the upper jaw, a lower-jaw attachment forrecording movements of the lower jaw relative to the upper jaw, and areference body, wherein the reference body can be connected in a fixedposition to the bite fork, wherein the bite fork and the reference bodyconnected to it in a fixed position are designed such that both theimpression and the reference body can be recorded by a scanningprocedure.
 2. Electronic register device of claim 1, wherein thescanning procedure is a continuous scanning procedure.
 3. Electronicregister device of claim 1, wherein the reference body can alternativelybe connected in a fixed position to the lower-jaw attachment. 4.Electronic register device of claim 1, wherein the reference body hasfirst form-fit elements, and the bite fork has second form-fit elements,such that, to produce the positionally fixed connection of the referencebody to the bite fork, the first form-fit elements can be brought into aform-fit engagement with the second form-fit elements.
 5. Electronicregister device of claim 4, wherein the reference body can alternativelybe connected in a fixed position to the lower-jaw attachment. 6.Electronic register device of claim 5, in which the lower-jaw attachmenthas third form-fit elements, such that, to produce the positionallyfixed connection of the reference body to the lower-jaw attachment, thefirst form-fit elements can be brought into another form-fit engagementwith the third form-fit elements.
 7. Electronic register device of claim1, wherein the reference body has several pin-shaped or hemisphericalscan elements.
 8. Electronic register device of claim 7, wherein thereference body has at least three said scan elements.
 9. Electronicregister device of claim 7, wherein the scan elements protrude from aplane surface of the reference body.
 10. Electronic register device ofclaim 7, in which at least two of the scan elements have differentshapes.
 11. Electronic register device for recording movements of thelower jaw of a person relative to the upper jaw of the person, theregister device comprising: a bite fork for recording a position of theupper jaw relative to reference points on the head of the person,wherein the bite fork is designed to receive a plastic compound forrecording an impression of the dentition of the upper jaw, and alower-jaw attachment for recording movements of the lower jaw relativeto the upper jaw, wherein the bite fork has a first reference bodyconnected in a fixed position to the rest of the bite fork, and thelower-jaw attachment has a second reference body connected in a fixedposition to the rest of the lower-jaw attachment, wherein the bite forkis designed in such a way that both the impression and also the firstreference body can be recorded by a scanning procedure.
 12. Electronicregister device of claim 11, wherein the scanning procedure is acontinuous scanning procedure.
 13. Electronic register device of claim11, wherein the first reference body and the second reference body eachhave several pin-shaped or hemispherical scan elements.
 14. Electronicregister device of claim 13, wherein the reference body has at leastthree said scan elements.
 15. Electronic register device of claim 13,wherein the scan elements protrude from a plane surface of the referencebody.
 16. Electronic register device of claim 13, in which at least twoof the scan elements of the first reference body have different shapesand/or at least two of the scan elements of the second reference bodyhave different shapes.